The detectability of a tone added to a masker is superior when the detection trial is preceded by the masker than the signal-plus-masker. This auditory enhancement can withstand long temporal gaps between the precursor and the trial, suggesting that for yes/no trials sensitivity may depend on the stimulus presented in the prior trial. The results from an experiment examining the detectability of a 1000-Hz tone added to 6-tone maskers confirmed sequential effects on sensitivity. The values of d' were higher when the prior trial was a no-signal (masker alone) trial compared to a signal (signal-plus-masker) trial.